Introduction: The knee joint, the largest joint in the body, has several functionsrnwhich are essential for human beings to walk, run and jump. Primarily, it enablesrnflexion-extension of the lower limb in the sagittal plane. Joint stability duringrnmovement is attained by the shape of the articular surfaces, the collateral andrncruciate ligaments, the menisci and tendons and muscles crossing the knee joint.rn(1) The vulnerability of the knee, the largest joint in the body, to direct traumarnmakes knee injuries very common throughout life. (2)rnMRI visualizes most components of the knee joint, including articular cartilage,rnmenisci, intra-articular ligaments, synovium, bone marrow, subchondral cysts, andrnother periarticular and intra-articular lesions that are not detectable by radiography.rn(4).rnThe patterns of abnormalities of these different joint components as detected byrnMRI has been studied in different centers. Such types of studies, to date, have notrnbeen done in our country to our knowledge. The aim of this paper is to studyrnfrequency and the patterns of these abnormalities in the knee joint detected by kneernMRI.rnObjective: To assess the patterns of abnormalities in the knee joint detected byrnknee MRI.rnMethods: Hospital based prospective cross sectional study was conducted on 49rnpatients who had knee MRI at Tikur Anbessa Specialized Hospital for a period of 7rnmonths from January 1 to August 2016. Patients included here are those who hadrnknee MRI and no history of knee surgery.rnResults: A total of 49 patients were included in the study out of which 26(53.1%)rnwere male and 23 (46.9%) were female, with a mean age of 43 years (range 17 torn68 years). The three most common pathologies were joint effusion seen inrn32(65.3%), bone marrow edema in 22(45.8%) and osteophytes in 22(44.9%). ACLrntear was the commonest ligament abnormality occurring in 5 (10.4%) patients. Tenrn(20.8%) patients had meniscal tear, all involving the medial meniscus with thernposterior horn being involved in 8(80%) of these patients.rnConclusion: The mean age of our study population was higher than mostrnreferenced papers suggestive of possible delay in health seeking. The commonestrnknee pathologies were similar to other studies. Features of osteoarthritis were seenrnin higher frequency in our study population. Even though the higher mean agerncould be the possible cause, further study is recommended to look into the causes.rnBone fracture, tendon abnormality and ligament abnormality showed statisticallyrnsignificant association with trauma. These abnormalities which were seen withrnhigher frequency in those with a history of trauma were also observed in higherrnfrequency in the male population.